This invention relates to wire-connectors and more particularly to solderless connectors for making permanent electrical connection to the closely spaced wire conductors of compact flat cables.
Wire connectors for flat cables, as described in U.S. Pat. Nos. 3,434,093 and 3,444,506, employ bifurcate flat plate contact elements positioned in planes perpendicular to the wires. The elements are forced through the plastic insulation and onto the conductors, causing slight resilient separation of the two prongs in the plane of the plate and resulting in permanent spring compression reserve contact. The width of the elements must be sufficient to provide the required resiliency and avoid permanent deformation while still permitting the required separation, but must be substantially less than the spacing between adjacent wires in order that adequate insulation between wires and elements may be maintained. These requirements have been fully met in connectors for cables containing No. 28 or No. 30 gage solid copper wires on 0.05 inch centers. In such connectors the contact elements are required to have a width of at least four, preferably five times the thickness of the plate. For cables with more closely spaced wires, difficulty has occasionally been experienced with these prior art structures in obtaining fully effective contact while retaining required insulating value.
The present invention makes possible a significant reduction in the width of the contact element while still affording permanent full contact, and thereby permits the effective use of flat cables having extremely close wire spacings of the order of 0.0425 to 0.0250 inch.